java主要持久化操作_Java 持久化操作之 --XML

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.Result;

import javax.xml.transform.Source;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

import org.xml.sax.SAXException;public classXmlText {//private static Document parse;

public static voidmain(String[] args) throws Exception {//text();//add();//delete();//modfiy();

}/**

* 循环解析XML

*

* @throws ParserConfigurationException

* @throws SAXException

* @throws IOException*/

public static voidtext() throws ParserConfigurationException,

SAXException, IOException {//创建工厂

DocumentBuilderFactory factory =DocumentBuilderFactory.newInstance();//1.创建解析器对象

DocumentBuilder builder =factory.newDocumentBuilder();//2.创建文档对象

Document document = builder.parse("lbl/NewFile.xml");//3.拿到节点集合

NodeList list = document.getElementsByTagName("book");//4.遍历集合

for (int i = 0; i < list.getLength(); i++) {//拿到每个节点

Element item =(Element) list.item(i);//解析每个节点属性的值

String bookid = item.getAttribute("id");

String bookType= item.getAttribute("type");

System.out.println(bookid + "\t" +bookType);//解析每个节点的子节点的值

String bookName = item.getElementsByTagName("bookName").item(0)

.getTextContent();

String bookprice= item.getElementsByTagName("bookPrice").item(0)

.getTextContent();

String bookAuthor= item.getElementsByTagName("bookAuthor").item(0)

.getTextContent();

System.out.println(bookName + "\t" + bookprice + "\t" +bookAuthor);

}

}/**

* 添加节点

*

* @throws Exception*/

public static voidadd() throws Exception {//创建工厂

DocumentBuilderFactory newInstance =DocumentBuilderFactory

.newInstance();//创建解析器

DocumentBuilder newDocumentBuilder =newInstance.newDocumentBuilder();//创建文档对象

Document document = newDocumentBuilder.parse("lbl/NewFile.xml");//伪造节点

Element createElement = document.createElement("book");//给节点属性赋值

createElement.setAttribute("id", "004");

createElement.setAttribute("type", "动漫专题");//伪造节点的子节点

Element bookName = document.createElement("bookName");

bookName.setTextContent("樱桃小丸子");

Element bookPrice= document.createElement("bookPrice");

bookPrice.setTextContent("20");

Element bookAuthor= document.createElement("bookAuthor");

bookAuthor.setTextContent("无名");//将三个节点绑定到一个节点下。变成某一节点的子节点

createElement.appendChild(bookName);

createElement.appendChild(bookPrice);

createElement.appendChild(bookAuthor);//把新建的节点，添加到根节点下

document.getElementsByTagName("books").item(0)

.appendChild(createElement);//将修改后的文件，重写到硬盘

TransformerFactory transformerFactory =TransformerFactory

.newInstance();//创建转换器

Transformer transfromer =transformerFactory.newTransformer();//要传入的数据源

Source source = newDOMSource(document);//要传入的路径

Result result = new StreamResult("lbl/NewFile.xml");//转换方法

transfromer.transform(source, result);

System.out.println("add ok");

}/**

* 修改节点

*

* @throws Exception*/

public static voidmodfiy() throws Exception {//创建工厂

DocumentBuilderFactory newInstance =DocumentBuilderFactory

.newInstance();//创建解析器

DocumentBuilder newDocumentBuilder =newInstance.newDocumentBuilder();//创建文档对象

Document document = newDocumentBuilder.parse("lbl/NewFile.xml");//拿到要修改的节点

Element item = (Element) document.getElementsByTagName("book").item(1);

item.getElementsByTagName("bookName").item(0).setTextContent("我是测试xx");//将修改后的文件，重写到硬盘

TransformerFactory transformerFactory =TransformerFactory

.newInstance();//创建转换器

Transformer transfromer =transformerFactory.newTransformer();//要传入的数据源

Source source = newDOMSource(document);//要传入的路径

Result result = new StreamResult("lbl/NewFile.xml");//转换方法

transfromer.transform(source, result);

System.out.println("add ok");

}/**

* 删除节点

*

* @throws Exception*/

public static voiddelete() throws Exception {//创建工厂

DocumentBuilderFactory newInstance =DocumentBuilderFactory

.newInstance();//创建解析器

DocumentBuilder newDocumentBuilder =newInstance.newDocumentBuilder();//创建文档对象

Document document = newDocumentBuilder.parse("lbl/NewFile.xml");//拿到要删除的节点

Element item = (Element) document.getElementsByTagName("book").item(2);

document.getElementsByTagName("books").item(0).removeChild(item);//将修改后的文件，重写到硬盘

TransformerFactory transformerFactory =TransformerFactory

.newInstance();//创建转换器

Transformer transfromer =transformerFactory.newTransformer();//要传入的数据源

Source source = newDOMSource(document);//要传入的路径

Result result = new StreamResult("lbl/NewFile.xml");//转换方法

transfromer.transform(source, result);

System.out.println("delete ok");

}

}

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